Module org.cicirello.chips_n_salsa
Class PermutationInitializer
java.lang.Object
org.cicirello.search.operators.permutations.PermutationInitializer
 All Implemented Interfaces:
Splittable<Initializer<Permutation>>
,Initializer<Permutation>
The PermutationInitializer provides metaheuristic implementations, such as of simulated
annealing, etc, with a way to generate random initial solutions to a problem, as well as a way to
make copies of current solution configurations. Since it implements the
Initializer
interface, which relies on generics, such implementations of search algorithms such as simulated
annealing, etc, do not need to know the representation of solutions.
This initializer generates permutations uniformly at random from among the space of permutations. This is the typical case for many metaheuristics (e.g., hill climbers and simulated annealers often begin at a random solution).

Constructor Summary

Method Summary
Modifier and TypeMethodDescriptionCreates one candidate solution to a problem.split()
Generates a functionally identical copy of this object, for use in multithreaded implementations of search algorithms.

Constructor Details

PermutationInitializer
public PermutationInitializer(int n) Constructs a PermutationInitializer. Parameters:
n
 The length of the permutations generated by this permutation initializer. n must be nonnegative. Throws:
IllegalArgumentException
 if n is negative.


Method Details

createCandidateSolution
Description copied from interface:Initializer
Creates one candidate solution to a problem. Specified by:
createCandidateSolution
in interfaceInitializer<Permutation>
 Returns:
 a candidate solution to a problem instance.

split
Description copied from interface:Splittable
Generates a functionally identical copy of this object, for use in multithreaded implementations of search algorithms. The state of the object that is returned may or may not be identical to that of the original. Thus, this is a distinct concept from the functionality of theCopyable
interface. Classes that implement this interface must ensure that the object returned performs the same functionality, and that it does not share any state data that would be either unsafe or inefficient for concurrent access by multiple threads. The split method is allowed to simply return the this reference, provided that it is both safe and efficient for multiple threads to share a single copy of the Splittable object. The intention is to provide a multithreaded search with the capability to provide spawned threads with their own distinct search operators. Such multithreaded algorithms can call the split method for each thread it spawns to generate a functionally identical copy of the operator, but with independent state. Specified by:
split
in interfaceSplittable<Initializer<Permutation>>
 Returns:
 A functionally identical copy of the object, or a reference to this if it is both safe and efficient for multiple threads to share a single instance of this Splittable object.
